1. Field of the Invention
This invention relates to a photographic exposure time control device, and more particularly, to an exposure time control device for use in a cinecamera.
2. Description of the Prior Art
Constructions are presently known according to which, in order to vary the exposure time in a cinecamera, one must adjust either the angle of opening of the shutter blade or the time required for the opening of the shutter blade to traverse the aperture (the opening for picture-taking), that is, the rotational speed at which the shutter blade traverses the aperture. A typical type of the former design is that in which the angle of opening is varied directly by two blades, and an example of the latter design is that in which the rotational speed of the shutter itself is varied during one-frame photography (one complete rotation) with the number of revolutions of the shutter blade driving motor maintained constant.
However, both of these known designs require very complicated constructions.